/Engine/Plugins/Developer/Concert/ConcertMain/Source/ConcertTransport/Public/IConcertEndpoint.h
Add a Request Handler
void InternalAddRequestHandler ( const [FTopLevelAssetPath](API\Runtime\CoreUObject\UObject\FTopLevelAssetPath) & RequestMessageType, const [TSharedRef](API\Runtime\Core\Templates\TSharedRef)< [IConcertRequestHandler](API\Plugins\ConcertTransport\IConcertRequestHandler) > & Handler )